Drill guide and stop



June 16, 1959 R. w. MCLANE 2,890,607

DRILL GUI-DE AND STOP Filed Aug. '7, 1956 2 Sheets-Sheet 1 Fig./ Fi .2

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' Robe/'7 W, Mc Lane Fig. 5 INVENTOR. r5 72 74 93 73 I 92 J V wfi fi%United States Patent Ofiice 2,890,607 Patented June 16 1959 DRILL GUIDEAND STOP Robert W. McLane, Dayton, Ohio Application August 7, 1956,Serial No. 602,617

4 Claims. (Cl. 77-62) This invention relates to a drill accessory andpartic ularly to a combination drill guide and stopwhich features bothconvenience and accuracy in the use thereof.

It is common experience of craftsmen who use hand tools, andparticularly electric hand drills, that to drill a hole exactlyperpendicular to the surface being penetrated is uncommonly difiicnltwithout an aid of one type or another. Generally when an accurateperpendicular hole is desired the operation is performed on a drillpress. It is a common experience in drilling a hole with a hand drill toaparticular depth, particularly in a thin piece of stock, that it isquite difficult without some makeshift or unhandy depth gauge to havethe hole exactly the desired. depth. Accordingly, an object of thepresent invention is to provide a device which alleviates diflicultiesinvolved in both. these operations that is, obtaining perpendicularholes in a work piece and drilling to a preselected depth with accuracy.

Another object of the present invention is to provide an accessory for ahand drill which does not in any way become mechanically connected orcoupled to the hand drill, but which coacts with the drill bit in such away that the same accuracy is achieved in its use as if it were attachedmechanically to the hand drill.

A further object of the present invention is to providean accessoryhaving a base with a smooth flat surface that rests on the work piece,this base being formed with a passage that is in alignment with acorresponding passage on a guide, the guide being easily adjustabletoward and away from the base, but in any position of adjustment the twopassages being retained in perfect alignment.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

Figure 1 is a side elevational View of an accessory which is constructedin accordance .With the principles of the invention, this accessorybeing shown in use on a work piece and with a fragmentary'part of adrill that is fitted with a drill bit;

Figure 2 is an end view of the accessory of Figure 1, this view being inelevation;

Figure 3 is a top plan view of the structure in Figure 2;

Figure 4 is an enlarged sectional view taken on the line 44 of Figure 1;

Figure 5 is an enlarged sectional view taken approximately on the line55 of Figure 1;

Figure 6 is a sectional view taken on the line 6-6 of Figure 1;

Figure 7 is a perspective view of another accessory which has beenconstructed in accordance with the principles of the invention;

Figure 8 is a sectional view taken on the line 8--8 of Figure 7; and

Figure 9 is a sectional view taken on the line 9-9'of Figure 7.

The accessory 10 of Figures 1-6 is used as an accessory, as opposed tothe attachment which will be secured mechanically to the hand drill 12.The accessory is'a device that would be rested on the surface of a workpiece, for example typical work piece 14, after a mark is made with apunch, or a pilot hole drill or the Work piece marked in some way toindicate the location of adesired hole. The drill 12 is of ordinary formand includes a chuck 18 together with a drill bit 20 carried by thechuck.

The accessory has a base 22 with a fiat bottom surface which is wider atone end than the opposite end. Boss 24 rises from the surface of base 22and has a' pair of guide rods 26 and 28 which protrude upwardlytherefrom. These guide rods are secured to the base and are parallel andspaced from each other, They are in a plane with a passage 30 formed atthe narrow end of the base 22 and through which the drill bit 20 isadapted to be passed (Figure l). Passage 30' is formed by drilling. thencounterboring to provide a bore 32' and a counterbore 34- separated by asloped shoulder 36-, the counter bore being nearer to the top surface ofthe base 22- and in a boss 38 which rises from said top surface of thebase. The reason for this construction is to facilitate the visualplacing of the accessory over'the mark on the work where the hole is tobe drilled and to facilitate insertion of the drill. through the baseguidehole. Thebottom surface of. the base is an accurate work piececon-' tacting surface and is perpendicular to guide rods 26 and 28 andto the common center line or axis of passage 30" and passage 40 that isformed in guide 42.

The guide 42 comprises an arm 44 that has 'a'sl'ot opening through oneend thereof. Pairs of confronting channels 47, 48 and 49, 50 are formedin the amt 44- of guide 42 and through slot 46. Guide rods 26 and 28pass through these pairs of' confronting channels in order to form waysfor the movement of guide 42 with respect to' base 22. There are meansfor holding the guide 42 in a fixed position on the pair of guide rods26 and 28. It is preferred that these means be of simple construction-'-for quick and convenient locking action. The belt with a thumb nut 58,or fillister or other type head in a; half threaded hole 56 in guide 42and washer 60 are: operatively associated such that upon rotation ofthe; thumb nut 58 the part of the guide on opposite sides of slot 46will tightly clamp the channels against the rods- 26 and 28.

In using the accessory 10- work piece 14'is marked in order to locatethe hole. Should it be desired that this hole he perpendicular to thesurface of the workpiece 1 4 and there be no requirement for the depthof the hole, guide 42 neednot be adjusted toany specific station; on.guide rods 26 and 28. However, if the depth of penetration of the drillbit 14 is of consequence, the drill is arranged with its bit 20 passedthrough the aligned passages in the guide and base. The distance thatthe bit passes through the bottom surface 62 of base 22 will be the sameas the depth of penetration of the drill bit into the work piece. Theguide 42 is adjusted accordingly to touch the drill chuck.

Then, the accessory is placed on the work piece 14 and by sightingthrough both of the passages in a manner similar to the use of a riflepeep sight, the drill 12 is moved in such a direction that the drill bitpasses through the aligned passages 30 and 40 and into the work piece.When the chuck 18 lightly touches the top surface of the guide 42surrounding the passage 40, this signals that the proper depth ofpenetration of the drill bit 20 has been obtained. Accordingly, theupper surface of the guide around the passage 40 constitutes means forlimiting iece.

p Attention is now invited to Figures 7-9 which demonstrate that theprinciples of the invention may be practiced in other structuralembodiments. Here there is a base 70 which has a bottom work piececontactingsurface 71. Near one end of the base 70 there is a passage 72whichis formed of a bore 73 and counterbore 74 separated by aslopingwall 75. Passage 72 is similar in both function and construction to thepassage 30, while passage 78 in guide 79 is similar in construction andfunction to the passage 40 in guide 42. The guide 79 is made of a blockor panel whose opposite ends are disposed between the outer ends of apair of levers 80 and 81 respectively. Pivot pins, as screws 82 and 83pass through openings in the outer ends of levers 80 and 81 and arethreaded into tapped holes in the opposite ends of guide 79. This mountsthe guide for pivotal movement about an axis which is in plane parallelto but spaced from the plane of surface 71.

a The means for mounting the guide 79 in such position that it is alwaysparallel to the surface 71 as seen best in Figure 7 and include thepreviously mentioned levers 80 and 81. The lower ends thereof areconstrained to a path of travel that is parallel to surface 71. This isachieved by using a pin 85 which is secured to the lower ends of levers80 and 81 and which is located in a slot 88 which is in base 70. A pairof links 90 and 91 are pivoted at their lower ends by pivot pins andspacers 92 and 93 to the sides of base 70, the pivot pins establishing apivot axis which passes through the common center line of the passages79 and 72. The upper ends of links 90 and 91 are apertured as are themedial points of levers 80 and 81. Bolt 95 is passed through pairs ofthese apertures and a thumb nut 96 is on the bolt. Spacer 97 is locatedbetween the levers 80 and 81 and has bolt 95 passed through the centerof it. In this way when the thumb nut is loosened the levers may beadjusted, but when the thumb nut 96 is tightened, the levers becomefixed in place.

In use of this accessory it is placed on the work piece just as theaccessory 10, and under the same circumstances. In order to alter theposition of the guide 79 loosening the thumb screw 96 and manuallypushing the levers up or down is all that is necessary. Thereafter thethumb nut is tightened due to the fact that the links 90 and 91 are ofthe same length as one-half of either of the levers and they areconnected to the mid-points of the levers, any motion of the levers asconstrained by slot 88 and pin 85 will require guide 79 to remain alwaysin a plane parallel to the surface 71 and with the center line ofpassage 78 coincident with the center line of passage 72.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed,

. 2,890,607 r e r andaccordingly all suitable modifications andequivalents may be resorted to, falling within the scope of theinvention as claimed.

What is claimed as new is as follows:

1. An accessory for drilling comprising a base having an accurate lowersurface adapted to be located on a work piece, said base having a drillbit passage extending therethrough near one end thereof, an upper guideprovided with an upper drill bit passage, means carried by said base forreleasably clamping said upper guide at varying distances from said basebut with said passages on the same centerline which is normal to saidbase lower surface so that the depth of penetration of said drill bitinto a workpiece may be controlled, said means comprising a pair of rodsthat are fixed to said base and that are in parallel spaced relation,said guide having a slot at one end through the walls of which there arepairs of confronting channels, said rods being passed through said pairsof channels to thereby mount said guide on said rods, and meansconnected with said guide to draw said slot and channels together andthereby clamp on said rods.

2. The accessory of claim 1 and a surface of said guide surrounding saidpassage in the guide forming a stop to limit the penetration of thedrill bit into the work piece by having a part of the chuck holding thebit come into light contact with the last-mentioned surface.

3. An accessory for drilling comprising a base having an accurate lowersurface adapted to be located on a work piece, said base having a drillbit passage extending therethrough near one end thereof, an upper guideprovided with an upper drill bit passage, means carried by said base forholding said upper guide spaced from said base in selected positions butwith said passages on the same centerline which is normal to said baselower surface, said means comprising a pair of levers, said guide beingmounted for pivotal movement between the outer ends thereof and formovement about an axis which is in a plane parallel to said lowersurface of said base, means constraining the movement of the oppositeends of said levers to a plane parallel to said surface, a pair of linkspivoted at their lower ends to said base, and means pivotally connectingthe upper ends of said links to the medial parts of said levers.

4. The accessory of claim 3 wherein said connecting means includes afastener so that said links and levers may be selectively adjusted andlocked to locate said guide in a selected position with respect to saidbase thereby providing a stop for the drill in order to preselect theextent of drill bit penetration in the work piece.

' References Cited in the file of this patent UNITED STATES PATENTS458,581 Johnson Sept. 1, 1891 2,360,942 Ellerstein Oct. 24, 19442,622,458 Jenkins Dec. 23, 1952

